Objective:To explore whether a longitudinal integrated clerkship (LIC) model is more conducive to medical students' post competency and satisfaction with clerkships compared with the traditional block rotation clerkship.Methods:We selected 72 students who participated in graduating clerkships at The First Affiliated Hospital of Harbin Medical University from June 2018 to June 2019. They were equally divided into experimental group and control group to adopt LIC and traditional block rotation clerkship models, respectively. After completing the clerkships, the two groups were evaluated for post competency through objective testing of theoretical medical knowledge and basic clinical skills and rating of the other five competence items by the students themselves and their teachers. At the same time, a questionnaire was delivered to both groups for the degree of satisfaction with clerkships. The t-test and chi-squared test were performed using SPSS 23.0. Results:The objective tests and students' self-evaluation showed that the experimental group had significantly higher scores of theoretical medical knowledge [(8.02±1.11) vs. (7.50±0.97)], basic clinical skills [(7.63±0.90) vs. (6.93±0.73)], medical professional responsibility [(7.74±0.56) vs. (7.31±0.78)], clinical communication [(8.10±1.06) vs. (7.22±0.60)], team work [(7.84±0.62) vs. (7.11±0.69)], literature searching [(6.25±0.60) vs. (4.78±0.84)], and scientific research ability [(4.26±0.88) vs. (2.46±1.20)] compared with the control group (all P<0.05). The experimental group had significantly higher teacher-rated scores of medical professional responsibility [(8.03±0.74) vs. (6.59±0.70)], clinical communication [(7.95±0.73) vs. (6.87±0.67)], team work [(7.96±0.75) vs. (6.95±0.69)], literature searching [(4.84±0.84) vs. (3.30±0.69)], and scientific research ability [(4.53±1.03) vs. (2.70±1.05)] than the control group (all P<0.01). The scores of satisfaction were all higher in the experimental group than in the control group in terms of course arrangement satisfaction [(7.17±0.91) vs. 6.56±0.84)], teacher-student interaction satisfaction [(7.08±0.69) vs. (6.28±0.82)], self-improvement satisfaction [(7.28±0.45) vs. (6.36±0.49)], and clinical work smoothness [(7.72±0.82) vs. (6.81±0.71); all P<0.01]. Conclusion:Compared with the traditional block rotation model, the LIC model is more helpful for improving the post competency of medical students. LIC is a new clinical clerkship model that can potentially replace the traditional block rotation clerkship.

Objective:To evaluate the effect of transcutaneous electrical acupoint stimulation (TEAS) on mitochondrial quality control during endotoxin-induced acute lung injury (ALI) in mice.Methods:Twenty-four clean-grade healthy male C57BL/6J mice, aged 4-6 weeks, weighing 15-20 g, were divided into 4 groups ( n=6 each) according to the random number table method: control group (group C), endotoxin-induced ALI group (group L-ALI), endotoxin-induced ALI plus acupoint electroacupuncture group (group L-ALI+ EA), and endotoxin-induced ALI plus non-acupoint electroacupuncture group (group L-ALI+ SEA). Lipopolysaccharide (LPS) 15 mg/kg was injected via the caudal vein to develop the model of endotoxin-induced ALI in anesthetized mice.In group L-ALI+ EA, at 5 days before LPS injection, bilateral Zusanli and Feishu acupoints were stimulated with an electric stimulator for 30 min each time at a voltage of 1-2 mA and a frequency of 2/15 Hz until the end of the experiment.In group L-ALI+ SEA, stimulation was performed at the points 0.5 cm lateral to the acupoints of bilateral Zusanli and Feishu non-meridian and non-acupoint sites using the shallow puncture method, and the other treatment methods were the same as those previously described in group EA.Group C received no treatment.The mice were sacrificed by euthanasia at 12 h after LPS administration, and lung tissues were obtained for microscopic examination of the pathological changes (with a light microscope) and structure and morphology of mitochondria (with a transmission electron microscope) and for determination of the levels of reactive oxygen species (ROS) and mitochondrial DNA (mtDNA) and contents of glutathione (GSH) and glutathione oxidized (GSSG). The GSH/GSSG ratio was calculated.The expression of mitochondrial fusion proteins mitofusin 1 (Mfn1), Mfn2, optic atrophy1 (OPA1), dynamin-related protein 1 (Drp1), fission protein 1 (Fis1), peroxisome-proliferator-activated receptor γ coactivator-1α (PGC-1α), nuclear respiratory factor-1 (NRF1), NRF2, PTEN-induced putative protein kinase 1 (PINK1) and the E3 ubiquitin ligase (Parkin) was determined by Western blot. Results:Compared with group C, the level of ROS and contents of GSSG and mtDNA were significantly increased, GSH content and GSH/GSSG ratio were decreased, the expression of Mfn1, Mfn2, OPA1, NRF1, NRF2 and PGC-1α was down-regulated, and the expression of Drp1, Fis1, PINK1 and Parkin was up-regulated in L-ALI, L-ALI+ EA and L-ALI+ SEA groups ( P<0.05). Compared with group L-ALI, the level of ROS and contents of GSSG and mtDNA were significantly decreased, GSH content and GSH/GSSG ratio were increased, the expression of Mfn1, Mfn2, OPA1, NRF1, NRF2 and PGC-1α was up-regulated, and the expression of Drp1, Fis1, PINK1 and Parkin was down-regulated in group L-ALI+ EA ( P<0.05). Compared with group L-ALI+ EA, the level of ROS and contents of GSSG and mtDNA were significantly increased, GSH content and GSH/GSSG ratio were decreased, the expression of Mfn1, Mfn2, OPA1, NRF1, NRF2 and PGC-1α was down-regulated, and the expression of Drp1, Fis1, PINK1 and Parkin was up-regulated in group L-ALI+ SEA ( P<0.05). Conclusions:TEAS can reduce endotoxin-induced ALI probably through regulating mitochondrial quality control in mice.

Objective:To investigate the short-term efficacy of hip arthroscopy for different types of femoroacetabular impingement syndrome (FAI).Methods:A retrospective analysis was conducted of the 85 FAI patients who had been treated by hip arthroscopy at Department of Orthopaedic Surgery, General Hospital of Southern Theater Command of PLA from January 2016 to December 2018. They were 52 males and 33 females, aged from 19 to 59 years (average, 36.9 years). According to the anatomical morphology of the acetabulum and proximal femur, there were 26 cases of cam type, 16 cases of pincer type and 43 cases of mixed type. Routine hip arthroscopy was performed to remove the proliferative synovium. Femoral head and neck plasty was conducted for the cases of cam type, resection of the overly covered acetabulum followed by labral suture for those of pincer type, and resection of overly covered acetabulum and labral suture followed by femoral head and neck plasty for those of mixed type. Hip function was assessed one year after surgery using the modified Harris hip score (mHHS), nonarthritic hip score(NAHS), and hip outcome score activity of daily living scale (HOS-ADL); the alpha angle and central edge(CE) angle were measured after CT reconstruction.Results:The 85 patients were successfully followed up for an average of 21 months (range, from 12 to 48 months). The mHHS, NAHS and HOS-ADL for all the patients were improved significantly from preoperative 63.1±7.9, 62.5±7.5 and 62.3±7.9 to 83.4±8.7, 82.9±8.2 and 83.6±8.8 one year after surgery, respectively (all P<0.05) while the mHHS, NAHS and HOS-ADL for the patients of cam, pincer and mixed types were all significantly improved compared to their preoperative values (all P<0.05). The preoperative alpha angles for the cam and mixed types (67.3°±5.2° and 64.2°±5.2°) were significantly reduced to 50.3°±2.9° and 49.6°±2.8° one year postoperatively ( P<0.05); the preoperative CE angles for the pincer and mixed types (52.9°±4.6° and 50.9°±3.6°) were significantly reduced to 33.1°±4.5° and 31.3°±4.3° one year postoperatively ( P<0.05). Conclusion:Hip arthroscopy can effectively treat FAI of cam, pincer and mixed types, leading to good short-term efficacy.

Objective:To explore the short-term effect of arthroscopic posterior suture of the glenoid labial capsule in the treatment of recurrent posterior subluxation (RPS) of shoulder joint.Methods:A retrospective study was conducted on 16 RPS patients who had undergone arthroscopic posterior glenoid capsule folding suture from January 2016 to December 2018, including 12 males and 4 females, with an average age of 22 years (range, 18-37 years). 11 had full-thickness posterior glenoid tear (2 with SLAP injury, 7 with posterior capsular laxity), and 5 had partial posterior glenoid tear (5 with posterior capsular laxity). All 16 patients had active shoulder pain and had undergone arthroscopic posterior glenoid capsule folding suture with suture anchors. After surgery, shoulder abduction was fixed with a sling for 6 weeks to prevent internal rotation of the shoulder; full range of active and passive activities were performed 2-3 months after surgery, and normal movement was resumed 6 months after surgery. Shoulder function was assessed using the American Society of Shoulder and Elbow Surgery (ASES) score and the University of California at Los Angeles (UCLA) end-result score, and shoulder stability was assessed using the instability score in the ASES score.Results:All 16 patients were followed up for 19 months (range, 12-36 months). The shoulder instability score was reduced from 7.6±1.6 preoperatively to 2.0±1.2 postoperatively ( t=5.562, P< 0.001); the ASES score was improved from 45.9±9.8 preoperatively to 85.8±6.1 ( t=39.937, P< 0.001); the pain score was increased from 18.9±5.4 preoperatively to 40.9±4.2 ( t=22.063, P< 0.001); the daily life score was improved from 27.0±7.8 preoperatively to 44.9±3.4 ( t=17.875, P< 0.001), and the UCLA score was improved from 16.1±4.5 preoperatively to 31.9±2.6 ( t=15.813, P< 0.001). One patient had pain during boxing 12 months after surgery, and all patients had significant improvement in shoulder weakness and instability. No patient had instability recurrence. Magnetic resonance showed sutured posterior labrum tearhealed. Conclusion:Arthroscopic posterior glenoid capsule folding suture can repair the labrum injury and restore the tension of the posterior capsule. The glenoid capsule complex healed can increase the posterior obstruction of the scapula. This method can effectively treat RPS with good short-term efficacy.

Objective To study the feasibility and early efficacy of matrix?induced autologous chondrocyte implantation repairing knee joint cartilage injury. Methods The Matrix?induced autologous chondrocyte implantation was used to repair knee joint cartilage injury in 13 cases (11 males and 2 females) with knee joint cartilage injury from April 2012 to March 2013. The av?erage age was 27.5 years old. All cases were suffering from unilateral focal cartilage defect of knee joint with International Carti?lage Repair Society (ICRS) chondral defect classification system grade III or IV, visual analogue scale (VAS)>3, and all of which had corresponding pain symptoms. The average defect area was 4.2 cm2. Standardized rehabilitation exercise was carried out after matrix?induced autologous chondrocyte implantation. Patients were followed up for 1 years, and knee injury and use osteoarthritis outcome score(KOOS), International Knee Documentation Committee (IKDC), subjective knee form and Lysholm score were col?lected to assess the function. Meanwhile, magnetic resonance observation of cartilage repair tissue (MOCART) score was used to assess the magnetic resonance imaging. Results All patients had been followed?up for 1 year. One patient had meniscus repair under arthroscopy for the meniscus injury caused by downstairs sprain in 6.5 months postoperative, so the score of 12 months post?operative was excluded. The knee range of motion was decreased in 3 months postoperative (123.1°±8.0°) compared to preopera?tive one (135.4°±5.7°), and has no difference in 6 months (136.1°±6.1°) and 12 months postoperative (135.1°±3.6°) compared to preoperative one. The 5 subsets of KOOS score were decreased in 3 months compared to preoperative one, and were significantly increased in 6 months and 12 months. The IKDC has no difference in 3 months (26.1±3.9) compared to preoperative one (43.5± 6.5), and were significantly increased in 6 months (53.3±5.8) and 12 months (62.8±7.2) compared to preoperative one. The magnet?ic resonance observation of cartilage repair tissue (MOCART) score was increased in 12 month(73.3±17.9)compared to preopera?tive one(51.5 ± 12.6). Conclusion MACI is a good technology for knee joint cartilage injury. It has a good clinical effect on re? pairing cartilage injury effectively and restoring the function of knee joint.

BACKGROUND:The methods used to repair articular cartilage defects currently have the cons and pros. Fibrocartilages are commonly used to repair tissues, and the fibrocartilage lacks of the tissue biomechanical properties and chemical properties of normal hyaline cartilage. OBJECTIVE:To investigate the feasibility of biological osteochondral xenogenic graft transplantation to repair articular cartilage defects. METHODS:The normal goats were randomly divided into two groups. The donor pig knee joints were the experimental group. Cylindrical osteochondral with the diameter of 4.5 mm and length of 10 mm were col ected with the Smith&Nephew osteochondral transplantation device, and the patented technology was used for deantigen. The donor goat knee joint osteochondrals were the control group and preserved with cryopreservation. The lesions on femoral trochlea and weight-bearing surface of medial condyle were selected respectively for osteochondral implantation, and the animals were sacrificed at 16 and 32 weeks after operation for the general and pathological section observation. RESULTS AND CONCLUSION:General observation in the experimental showed that the lesions were covered by fibroid tissue;some cartilage of the grafts turned yel ow and there was clear boundary between the surface and the peripheral cartilages;the general and section observation under microscope showed that lesions of the control group were covered by the grafts basical y, and cracks could be seen on the edge of the transplant part. The results show that there is difference between effects of biological osteochondral xenogenic graft transplantation and osteochondral al ograft transplantation for the repairing of articular cartilage defects, and osteochondral al ograft transplantation bas better effect.

Objective To investigate the clinical results of posterior cruciate ligament (PCL) reconstruction by double bundle-double tunnel Y-shape of the anterior tibialis tendon allograft. Methods From March 2001 to January 2008, 47 patients underwent PCL reconstruction were included. The allogeneic adult anterior tibialis tendon was prepared into the Y-shape double bundles with the length of 130 mm; A bundle was defined as A-side; B-side was two short bundle (B1, B2 bundle). A bundle was 70 mm in length with a diameter of 10-12 mm. B1 bundle (anterolateral bundle) was 55 mm long with a diameter of 6 mm; B2 bundle(posteromedial bundle) was about 50 mm with a diameter of 6 mm. The allograft ligament was installed through the antero-medial approach. Absorbable interface screws were fixed in the tibial tunnel firstly, and then in the femoral tundles. When being fixed, anterolateral bundle was in flexion of 90°, postero-medial bundle was in 30°. Assisted exercise with knee an angle-locked walking aid had continued for 8-10 weeks. Results The average operating time were 45 min. The average follow-up time was 49.5 months. Preoperative Lachmann was positive in all cases while Lachmann was negative in 39 cases, weakly positive in 5 cases, and positive in 4 cases postoperatively. Post-operative KT-1000 testing, Lysholm score and Tegner activity levels has improved significantly compare with the pre-operative ones. Conclusion The double folded bundles of adult anterior tibialis tendon has sufficient length and diameter for posterior cruciate ligament reconstruction with power tension. The methods of ligament passing through the tunnel has improved to ease the procedure.

BACKGROUND: Meniscus injury is a common sports injury of knee joint. Severe meniscus injury is difficult for clinical treatment due to the blood supply features. Effective repair of meniscus injury can prevent osteoarthritis of knee joint. OBJECTIVE: To review meniscus injury repair and transplantation replacement treatment of meniscus injury.METHODS: A computer-based online search of CNKI (www.cnki.net) and Medline database (www.pubmed.com) was performed for related articles published between January 2000 and March 2009, with the keywords "meniscus, repair, transplanted replacement therapy" in Chinese and English. Unrelated and repetitive studies were excluded. A total of 29 articles were included.RESULTS AND CONCLUSION: There are a number of treatment for meniscus injury, and indications and appropriate repair methods are very important. Xenogenic meniscus transplantation and tissue-engineered meniscus provide novel approach for meniscus injury repair, in particular the repair of avascular zone. However, the two methods require validation of immunology,epidemiology, anatomy, biomechanics, and clinical effect.

BACKGROUND: Lateral collateral ligaments play an important role in maintaining knee stability.Motion reduction of knee joint can be realized and the changes laws of medial and lateral collateral ligaments' length after anterior cruciate ligament(ACL)injury during weight-bearing flexion can be obtained via 2D/3D image registration technique.OBJECTIVE: To study in vivo stability of length changes of the medial and lateral collateral ligaments of ACL injury knee during weight-bearing flexion.METHODS: Eight volunteers with unilateral ACL rupture and contralateral normal knees,was captured CT images and 2orthogonal images of the knee at 0,15°,30°,60°,and 90° of weight-bearing flexion.These orthogonal images were used to recreate the in vivo knee positions at each of the targeted flexion angles by the method of 2D/3D image registration.Through the bone insertion of medial and lateral collateral ligaments,the elongation changes of medial and lateral collateral ligaments were obtained.RESULTS AND CONCLUSION: At 0°,15° and 30°,the length of medial collateral ligament of ACL injury knees was longer than normal knees,but the lateral collateral ligaments length of ACL injury knee was shorter than that of normal knees.All the differences have statistical significances(P < 0.05).The findings demonstrated that,at 0°,15° and 30°,the medial collateral ligament length of ACL injury knees was longer than normal knees,but lateral collateral ligaments length of ACL injury knees was shorter than normal knees.

BACKGROUND:Bone tumors around the Ⅱ section of pelvis are difficult to treat due to complicated anatomic structures.Using computer-aided technique,the excision range and prosthesis preparation can be individualized,which may obtain notable therapeutic efficacy in treating pelvic fractures in the clinic.OBJECTIVE:To discuss the application and the clinic effect of computer-aided technique in bone tumors therapy around the Ⅱsection of pelvis.METHODS:The pelvis model was generated with its CT data by rapid prototyping.Simulated bone resection and reconstruction were performed on the models.Then we designed surgical extension and made hemi-pelvic.Eight cases received resection of pelvic tumor and reconstruction based on computer-aided technique.RESULTS AND CONCLUSION:The resection of tumor and implantation of prosthesis were easily accessible.Two cases relapsed and 1 case loosened at 2 years after operation.According to Harris scoring criteria after total hip replacement,the scores of cases were well.The simulated resection and reconstruction of bone tumors around the Ⅱ section of pelvis based on computer-aided technique makes the operation easy and reconstruction precise,which produces good clinic results and offers a good promise for the application.